Lee Jasper, the controversial activist and former advisor to Ken Livingstone, has sparked anger after tweeting about the attempted armed mugging of Tony Blair's daughter Kathryn on a London street.

Mr Jasper, who is now a Respect Party activist, tweeted: "Quoting one of me heroes I say 'Chickens coming home to roost' #ViolenceBegetsViolence".

The tweet is a reference to the statement from Muslim minister and human rights activist Malcolm X after the assassination of John F Kennedy in November 1963.

Kathryn Blair, 25, was walking her dog with a group of friends and her boyfriend near her home when she came face to face with two men, one armed with a gun, who demanded cash and jewellery before fleeing empty-handed.

The daughter of the former Prime Minister and her partner were said to be shocked by the incident, but were unhurt. Scotland Yard confirmed an incident involving two male suspects with a gun took place in Ivor Place, Marylebone, at 8.30pm on Monday night.

Mr Jasper's comments were condemned as “appalling” and “contemptible” by other Twitter users.